Earth Talk

From the editors of E/The Environmental Magazine

Dear “Earth Talk”: Someone told me that
methane gas emitted by cows is a major contributor to global warming. I
thought it was a joke, but is this true? — David Rietz, Goose Creek, S.C. Accumulation of methane in the Earth’s
atmosphere has nearly doubled around the globe over the past 200 years.
Scientists believe that rising concentrations of this “greenhouse
gas,” which absorbs and sends infrared radiation to Earth, are
causing changes in the climate and contributing to global warming.Livestock animals naturally produce methane as part
of their digestive process, belching it while chewing cud and excreting it
in their waste. According to the Worldwatch Institute, 15 to 20 percent of
global methane emissions comes from livestock. John Robbins, author of The Food Revolution and Diet for a New America, says
that methane is 24 times more potent a greenhouse gas than carbon dioxide,
the culprit normally at the center of global-warming discussions. And there are plenty of sources: The U.S. Department
of Agriculture reports that animals in the U.S. meat industry produce 61
million tons of waste each year, which is 130 times the volume of human
waste produced, or 5 tons for every U.S. citizen. In addition to its impact
on climate, hog, chicken, and cow waste has polluted some 35,000 miles of
rivers in 22 states and contaminated groundwater in 17 states, according to
the U.S. Environmental Protection Agency. Ronnie Cummins, national director of the Organic
Consumers Association, says that a food chain with meat at its top is
unsustainable not only as a major contributor of greenhouse gases but also
with regard to inefficient dedication of large amounts of acreage to
livestock grazing. The USDA, for example, says that growing the crops
necessary to feed farm animals requires nearly 80 percent of
America’s agricultural land and half of its water supply. In addition, animals raised for food in the U.S.
consume 90 percent of the country’s soy crop, 80 percent of its corn
crop, and 70 percent of its grain. “If all the grain currently fed to
livestock in the United States were consumed directly by people, the number
of people who could be fed would be nearly 800 million,” says Cornell
ecologist David Pimentel. He adds that irresponsible livestock farming is
directly or indirectly responsible for much of the soil erosion in the
United States. Unfortunately, environmental problems associated with
livestock rearing are not limited to the United States. According to the
international environmental journal, Earth
Times, meat production grew more than fivefold
worldwide during the latter half of the 20th century. And as intensive
“factory” farming methods of raising livestock spread from the
United States to other countries — many with regulatory monitoring
and enforcement standards far worse than our own — this form of
pollution is sure to play an increasingly larger role in environmental
problems moving forward. For more information: Organic
Consumers Association, www.organicconsumers.org; Worldwatch Institute,
www.worldwatch.org. Send questions to “Earth Talk” in care of E/The Environmental Magazine, P.O. Box 5098, Westport, CT 06881; or e-mail
earthtalk@emagazine.com.